Obesity is a pandemic issue that has been reported to affect at
least 400 million adults worldwide, with this figure predicted to reach
approximately 700 million by 2015 (World Health Organization, 2005). Of
major concern is that obesity is associated with numerous comorbidities
such as hypertension, diabetes and hypercholesterolemia, which can
result in cardiovascular morbidity and mortality (Stein and Colditz,
2004).

Whilst caloric restriction is a common strategy used for
weight-loss, a combination of caloric restriction and exercise has been
shown to be a more effective non-surgical intervention (Curioni and
Lourenco, 2005). This combination has been shown to reduce the loss of
fat-free mass (Marks et al., 1995), promote fat loss (King et al.,
2001), maintain or minimise a fall in resting metabolic rate (RMR:
Lennon et al., 1985), reduce visceral adipose tissue depots (Ross, 1997)
and improve blood lipids (Dattilo and Kris-Etherton, 1992). Importantly,
exercise can improve aerobic fitness, which can directly reduce the risk
of co-morbidities associated with obesity (Mann, 1974). The exercise
regime commonly employed in obese populations involves continuous
aerobic exercise performed at a constant low to moderate intensity
(Jacobsen et al., 2003). However, this mode of exercise may not be the
most effective modality for fat-loss or health improvement.
High-intensity exercise burns more calories when compared to lower
intensity exercise performed over the same time period and can also
result in greater energy expenditure and fat oxidation post exercise
(Kaminsky and Whaley, 1993; King, et al., 2002; Tremblay et al., 1994).
In addition, O'Donovan et al. (2005) reported greater improvements
in total cholesterol, low density lipoprotein (LDL-C) and high density
lipoprotein (HDL-C) after 24 weeks of high-intensity exercise (80%
V[O.sub.2peak]), compared to moderate-intensity exercise (60%
V[O.sub.2peak]). However, continuous high-intensity exercise places a
greater physiological load on the cardiovascular system and may be
difficult for sedentary, obese individuals to undertake. This conjecture
is supported by Jakicic et al. (2004) and Ballor et al. (1990) who
reported the need for obese participants to split their exercise
sessions into series of shorter bouts due to their inability to perform
a single continuous session of moderate to high-intensity exercise.

Of relevance, interval training involves bouts of high-intensity
exercise interspersed with periods of rest or lower intensity exercise
that allow for partial recovery (McArdle et al., 2001). The intensity
and duration of the interval bouts can be manipulated in order to match
an individual's fitness level, thereby making this form of training
a suitable option for most individuals. To date, the few studies that
have compared interval training to continuous aerobic exercise in an
obese population have reported that interval training resulted in higher
V[O.sub.2peak] and RMR (King et al., 2002), greater fat loss (King et
al., 2001; Trapp et al., 2008) and an excess post oxygen consumption
(EPOC) that was longer and of greater magnitude (Kaminsky and Whaley,
1993). However, none of these studies included a caloric restriction
component, while Trapp et al. (2008) did not match work or exercise
intensities between groups. Further, Kaminsky and Whaley (1993) assessed
the effects of interval exercise on EPOC only. Therefore, the aim of
this study was to compare a 12-week home-based, intermittent, interval
exercise programme and caloric restriction (defined as 'diet'
throughout this manuscript hereon) to an intermittent continuous aerobic
exercise programme and diet on cardiovascular fitness, body composition,
resting metabolic rate and blood lipids in an obese population.

Methods

Forty-four sedentary, obese individuals (body mass index: BMI
[greater than or equal to] 30 kg x [m.sup.-2]), aged between 18 and 65
years, who had just joined a weight loss agency, volunteered for the
study. Potential participants were excluded if they participated in more
than 30 min of exercise on 3 occasions per week over the previous 6
months. Participants were also excluded if they were pregnant, taking
certain medications (i.e. beta blockers, blood pressure or thyroid
medication), were diabetic, had a blood pressure (BP) greater than
160/90, had lost more than five kg in the last three months, or had
musculoskeletal problems that prevented them from walking. A power
analysis was performed based primarily on results from King et al.
(2001; effect size 0.82) and it was calculated that 13 participants were
needed per group in order to detect an effect at an alpha of 0.05 with
an 80% confidence level (Cohen, 1988). Participants were matched
according to age, gender and BMI and then randomly stratified into
either an interval (INT) exercise and diet group or a continuous (CON)
aerobic exercise and diet group using a computer generated programme.
The matching process resulted in the exclusion of 4 participants who
could not be found a suitable match, while a further 14 participants
withdrew from the study for reasons due to time constraints (n = 7),
work commitments (n = 3), sickness (n = 1), holiday (n = 1), could not
be contacted (n = 1) and pregnancy (n = 1). This left 12 participants in
the INT group (9 females, 3 males) and 14 in the CON group (11 females,
3 males). Participants in both groups were on a similar strict caloric
diet during the intervention period which was monitored by the weight
loss agency. Participants were not blinded to their treatment due to the
nature of the intervention. The study was approved by the University of
Western Australian (UWA) Human Ethics committee and all participants
signed an informed consent form.

Physiological measures

Prior to the commencement of the intervention, participants were
required to attend the human performance laboratory between 06.00 and
09.00 hr where BMI was confirmed by measuring height (stadiometer) and
body mass (August Sauter GmbH D-7470 Albstadt 1 Ebingen, West Germany),
while blood pressure (BP) was also assessed after a 5 min rest. As
resting metabolic rate (RMR) is affected by the menstrual cycle (Donahoo
et al., 2004), all pre-menopausal females were required to make their
appointment during their luteal phase of their menstrual cycles
(Kaminsky and Whaley, 1993). Participants were required to avoid
exercise, as well as to have fasted in the 12-hr period prior to the RMR
test. During the RMR test, participants were required to lie quietly on
a bed for 30 min. Expired air was then collected over the final 20 min
period in a Tissot gasometer tank (Collins Inc, Braintree,
Massachusetts, USA). A gas analysis system consisting of an oxygen gas
analyser (Servomex Basic O2 Analyser, 500A, Susses, England) and a
carbon dioxide gas analyser (Datax Normocap CO2 moniotr, CD102, Helsink,
Finland) was used to measure samples of expired air. The gas analysis
system was calibrated prior to testing using three certified gravimetric
gas mixtures of known concentrations.

Body composition was then determined from a total body scan using a
GE Lunar Prodigy Vision Dual Energy X-ray Absorptiometry (DEXA) machine
(GE Medical Systems, Madison, WI) and accompanying software (enCORE
2004, GE Medical Systems, Lunar, Madison, WI). This software defines
android fat mass region by the area of the abdomen from the top of the
pelvis (lower boundary) to a proximal upper boundary that is 20% of the
distance between the top of the pelvis and the base of the neck. Arms
are excluded from this analysis. The upper boundary of the gynoid fat
mass region is defined by the top of the pelvis, with lateral boundaries
being the pelvis and outer thighs. The lower boundary for this region is
defined as a line distal to the upper boundary that is twice the height
of the android region. Calibration procedures were performed each day
prior to scanning while quality control was performed periodically on
the DEXA scanner during data collection. Test-retest analysis for body
composition using this particular machine has demonstrated high
reliability (r = 0.97).

Participants returned to the laboratory the following day where
V[O.sub.2peak] was determined using a graded exercise test (GXT) that
employed the Balke protocol (McArdle et al., 2001). Walking speed was
set at 5 kph, and the grade increased incrementally every 3 min until
the participant could no longer continue. During the GXT, ratings of
perceived exertion (RPE: Borg, 1982), BP and heart rate (HR) were
recorded at the end of every stage, while a 12-lead ECG (Cardiofax V
Ecaps 12 8370K, Nihon Kohden Corp, Japan) assessment was performed by a
clinical exercise physiologist. During the GXT, oxygen uptake was
calculated from minute ventilation, which was measured using mass flow
ventilometry and mixing chamber analyses of expired gas fractions (Vmax,
Sensormedics, Yorba Linda, CA). The gas analysers were calibrated prior
to each test using alpha (a) standard reference gases, while the flow
sensors were calibrated using a one litre syringe, as per manufacturer
specifications. Individual V[O.sub.2peak] was determined by averaging
the two highest consecutive V[O.sub.2] values recorded over a 20-s
period during the 2 min period prior to volitional exhaustion.

Finally, participants were required to provide a fasted blood
sample at a commercial pathology clinic that assessed total cholesterol
(TC), triglycerides, HDL-C, LDL-C, very low density lipoprotein (VLDL-C)
and coronary risk ratio (CRC: divides TC by HDL-C; McArdle et al.,
2001). All baseline measurements were repeated in the week following the
completion of the intervention.

Diet control

All participants participated in a strict diet programme developed
and monitored by a commercial weight loss organisation. The diet
consisted of a low carbohydrate (CHO; low glycemic) and moderate fat
diet, with the macronutrient breakdown being approximately 50% CHO, 30%
fat (mostly monosaturated) and 20% protein. Caloric intake was
individually restricted for all participants based on height and body
mass, with restrictions approximating 1200 kcals for women and 1400
kcals for men per day. Participants attended weekly weigh-ins at the
weight loss organisation. In order to sample dietary intake, all
participants were required to record their daily energy intake in a
diary during weeks 1 and 12 of the intervention. While this procedure
indicates dietary adherence for the time period monitored only, it can
be considered suggestive of overall dietary intake during the
intervention period. Instructions were given to all participants on how
to record their food intake in this diary. Information from this diary
was subsequently analysed using a computer software programme (FoodWorks
Professional Edition, Version 4, Xyris Software, Australia 2005).

Exercise interventions

Exercise in both groups consisted of home-based walking which was
performed on five days of the week over a 12-week period. Each exercise
session was divided into two 15 min bouts, with at least 3 h separating
each exercise bout. Walking intensity in the CON group was initially set
at HR values that equated to 50% of individual V[O.sub.2peak] determined
during the GXT. After 6 weeks, the exercise intensity was increased to
55% of individual V[O.sub.2peak] in order to account for any improvement
in aerobic capacity. Walking in the INT group was performed using a 2:1
min ratio of low-intensity (40% V[O.sub.2peak]) to moderate-intensity
(70% V[O.sub.2peak]) exercise, with these intensities increased to 45%
and 75% V[O.sub.2peak] after 6 weeks. These intensities were equated to
individual HR values determined during the GXT. Duration of exercise and
average relative exercise intensity (individual % V[O.sub.2peak] equated
to individual HR; bpm) were the same between groups for each exercise
session. All participants were given a HR monitor (Polar F3 Electro Oy,
Kempele, Finland) in order to monitor and maintain the correct exercise
(walking) intensity, while all exercise sessions were recorded in an
activity diary throughout the 12-week intervention. Fortnightly phone
calls were made to all participants over the course of the intervention
in order to check on progress and adherence to exercise sessions. All
participants were asked not to perform any additional exercise than that
prescribed for each intervention.

Daily activity data for a week (number of steps per day) was
assessed during weeks 1 and 12 of the intervention using a pedometer
(Yamax, Digi-walker, SW-700, Tokyo, Japan). The Yamax Digi-walker
pedometer has been reported to accurately and reliably measure steps
during walking and running in overweight and obese individuals (Swartz
et al., 2003).

Statistical analysis

Statistical analysis was performed using Statistical Packages for
Social Science, version 14.0 (Chicago, IL) for Windows with the alpha
set at p < 0.05. Independent t-tests were initially performed in
order to compare groups at baseline. All data was assessed using the
Levene's test for equality of variance. Baseline and
post-intervention scores for all variables were analysed using a 2
(group) by 2 (time) mixed design, repeated measures ANOVA. Post hoc
t-tests were performed if an interaction effect was significant (p [less
than or equal to] 0.05). The magnitude of the treatment effect was also
assessed using Cohen's d effect sizes (ES) and thresholds (< 0.5
= small; 0.5 - 0.79 = moderate; [greater than or equal to] 0.8 = large;
Cohen, 1988). Only moderate to large ES are reported.

Results

All results are reported as mean [+ or -] standard deviation. There
were no significant differences (p > 0.05) between groups at baseline
for age, body-mass, height and BMI (Table 1).

Aerobic fitness

Prior to the intervention, there were no significant differences (p
> 0.05) between the two groups for V[O.sub.2peak] (ml x [ kg.sup.-1]
x [min.sup.-1]) or time to exhaustion on a GXT (Table 2). While there
were no significant interaction effects for these variables upon
completion of the intervention (p > 0.05), there were significant
main effects for time for V[O.sub.2peak] (p < 0.001, d = 0.77 and
0.98 for the INT and CON groups, respectively), as well for time to
exhaustion (p < 0.001; d = 1.10 and 1.30 for the INT group and CON
groups, respectively). Details for resting HR (bpm), systolic blood
pressure (SBP), diastolic blood pressure (DBP) and final RPE values are
shown in Table 2. There were no significant differences between groups
for any of these variables at baseline, upon completion of the
intervention, or over time (p > 0.05).

Lipid Results and Coronary Risk Ratio

There were no significant differences between groups at baseline
for any of the blood lipid measures assessed (p > 0.05; Table 3).
Significant main effects for time (p < 0.05) were found for TC,
triglycerides, LDL and VLDL-C, with differences in values over time
resulting in moderate and large ES for triglycerides and VLDL-C in the
INT group only (d = 0.64 and d = 1.03, respectively). A significant
interaction effect was found for VLDL-C (p < 0.05), with post hoc
analysis showing a significant decrease in this measure in the INT group
only (p < 0.05; ES = 1.03; 39.1% vs 18.7% decline in the INT vs CON
group).

There was no significant difference in CRC between groups at
baseline, nor was there a significant interaction effect upon completion
of the intervention (p > 0.05; Table 3). There was however, a
significant main effect for time (p < 0.05), with the decrease in CRC
over the course of the intervention reflected by a moderate ES (d =
0.58) in the INT group only.

Body composition

There were no significant differences between groups for body mass,
fat mass or lean mass at baseline (p > 0.05, Table 4). While there
were no significant interaction effects for any of these variables upon
completion of the intervention (p > 0.05; Table 4), there were
significant main effects for time for body mass (p < 0.001) and fat
mass (p < 0.001). Large ES were found for the decline in fat mass
over the course of the intervention in both groups (d = 1.10 and 0.92 in
the INT and CON groups, respectively), while a moderate ES was recorded
for the decline in body mass over the course of the intervention in the
INT group only (d = 0.79). Further, while there were no significant
differences between groups for gynoid and android fat mass at baseline
or upon completion of the intervention (p > 0.05; Table 4), a
significant main effect for time was found for gynoid fat mass (p <
0.001), with decreases in this measure being reflected by large ES in
both groups (d = 0.94 and 0.84 in the INT and CON groups, respectively).

Resting metabolic rate

Resting metabolic rate values ([kcal x [d.sup.-1]) were similar
between the INT and CON groups prior to the intervention (1488 [+ or -]
256 and 1452 [+ or -] 312 [kcal x [d.sup.-1], respectively; p >
0.05). Additionally there were no significant differences in RMR between
groups post-intervention or over time (1434 [+ or -] 239 and 1406 [+ or
-] 192 [kcal x [d.sup.-1] for the INT and CON groups, respectively; p
> 0.05). Further, there were no significant differences in resting
respiratory quotient (RQ) between the INT and CON groups at baseline
(0.81 [+ or -] 0.07 and 0.78 [+ or -] 0.05, respectively; p > 0.05),
upon completion of the intervention (0.83 [+ or -] 0.05 and 0.80 [+ or
-] 0.05, respectively; p > 0.05) or over time (p > 0.05).

Adherence and diaries

Based on exercise diaries, adherence to exercise was 88% and 93%
for the INT and CON groups, respectively, with there being no
significant difference between these values (p > 0.05). All
participants were still enrolled in the diet programme at the
weight-loss agency upon completion of the intervention. Further, there
was no significant difference in the average total number of steps taken
per day (including exercise and incidental steps), as assessed by a
pedometer, between the INT and the CON groups during week 1 (10954 [+ or
-] 4150 steps and 9522 [+ or -] 2245 steps, respectively; p > 0.05),
and week 12 (11659 [+ or -] 4182 steps and 10567 [+ or -] 4476 steps,
respectively, p > 0.05), or over time (p > 0.05). Further,
assessment of a self-report food diary revealed no significant
differences in energy intake (kcal [d.sup.-1]) between the INT and the
CON groups during week 1 (1195 [+ or -] 83 and 1173 [+ or -] 97 kcal
[d.sup.-1], respectively) or week 12 (1255 [+ or -] 289 and 1193 [+ or
-] 62 kcal [d.sup.-1], respectively), or over time (p > 0.05).

Discussion

The aim of this study was to compare a 12-week home-based, diet and
interval exercise programme to a diet and continuous aerobic exercise
programme in order to determine which protocol resulted in greater
benefits in aerobic fitness, blood lipids, body composition and
metabolism. In general terms, while results demonstrated beneficial
effects associated with both interventions, only the combination of
interval training and caloric restriction resulted in significant
improvement in VLDL-C.

Results from this study showed that while there were improvements
in aerobic fitness in both groups over time, there were no significant
differences in these measures between groups post-intervention. This
outcome was surprising due to the number of studies that have reported a
higher V[O.sub.2peak] after high-intensity exercise compared to lower
intensity exercise (Adeniran and Toriola, 1988; King et al., 2001;
O'Donovon et al., 2005; Sokmen et al., 2002), even when total
energy was equal between interventions (King et al., 2001;
O'Donovan et al., 2005). Use of higher intensity exercise (80%
V[O.sub.2peak], Kraus et al., 2002; 80% V[O.sub.2peak], O'Donovon
et al., 2005; 90% [HR.sub.max], Adeniran and Toriola, 1988; 95%
V[O.sub.2peak], King et al., 2001; 120-150% V[O.sub.2]max, Sokmen et
al., 2002) than that used in the current study (intervals of 70-75%
V[O.sub.2peak]) may account for this discrepancy in results, as higher
intensity exercise places a greater overload on the cardiopulmonary
system, which in turn should result in greater improvements in fitness.
Further, while the need for adherence to exercise (frequency, intensity
and duration) and accurate reporting was stressed to participants, it is
possible that these requirements may not have been met, which in turn
may have contributed to the insignificant differences in aerobic fitness
between groups. Nonetheless, benefits observed in both groups,
demonstrated by increased time to exhaustion (NS) on the GXT of 5 min 33
s (INT group) and 5 min 20 s (CON group), translate to potential
improvement in cardiovascular outcomes, as a 1 min increase in treadmill
exercise time during a GXT has been associated with a reduction in
mortality (Blair et al., 1995).

Another health measure that is typically problematic in obese
individuals relates to a blood lipid profile that does not support
healthy function (O'Donovan et al., 2005). Normal values for blood
lipids are as follows: TC < 5.5 mM/L, triglycerides < 1.8 mM/L,
HDL-C = 1.1 3.5 mM/L, LDL-C < 3.5 mM/L and VLDL-C < 1.04 mM/L
(Safeer and Ugalat, 2002). Of relevance, results from this study
demonstrated that 12 weeks of diet and interval exercise resulted in TC
and LDL-C values approaching normal levels in the INT group. Further, a
significant improvement in VLDL-C over time was demonstrated in the INT
group only. These results may be due to baseline values that were in the
upper range for these measures in the INT group, whereas these measures
were well within normal range for the CON group. Further, the
significant decrease in VLDL-C over time in the INT group may explain
the lower CRC (NS; ES = 0.58; 18.7% vs 11.9% decline in INT vs CON
group) that occurred over the course of the intervention in this group.
Results from this study support other studies that have reported
improvement in blood lipids either after an exercise programme
(Weintraub et al., 1989; Sugiura et al., 2002) or following a diet
intervention (Dattilo and Kris-Etherton, 1992). Weintraub et al. (1989)
suggested that improvement in blood lipids as a result of exercise may
be due to greater lipoprotein lipase activity and a consequent reduction
in triglyceride levels. Lack of significant differences in blood lipids
between the two groups post-intervention may have been due to the short
intervention period used, as well as the use of exercise intensities in
the INT group that were not high enough to elicit change. For example,
O'Donovan et al. (2005) reported significant improvement in TC,
LDL-C and HDL-C after 24 weeks of exercise performed at 80%
V[O.sub.2peak].

Declines in total fat and gynoid fat mass were reflected by
significant main effects for time, as well as moderate and large ES in
both groups. In addition, the decrease in body mass over time
(significant main effect only) was reflected by a moderate ES in the INT
group only. This result for body mass in the INT group most likely
reflects the greater total fat and android fat mass loss in this group
(~22.5% and 28.5%) compared to the CON group (~17% and 19.2%), combined
with minimal changes over time between groups for lean mass and gynoid
fat mass. These results support other similar studies that reported body
mass loss (Schmidt et al., 2001; Volek et al., 2005) and fat mass loss
(King et al., 2001) after exercise interventions (King et al., 2001;
Schmidt et al., 2001) and a diet and exercise intervention (Volek et
al., 2005).

It was expected that the INT group would lose more fat mass
(including gynoid and android fat mass) compared to the CON group due to
reports of greater fat burning associated with higher intensity exercise
compared to lower intensity exercise (Tremblay et al., 1994; King et
al., 2001: King et al., 2002). While changes in body composition were
not significantly different between groups in the current study, the
percentage change experienced for total fat mass and android and gynoid
fat loss were higher in the INT group. As noted earlier, higher exercise
intensities, which may have resulted in greater improvement in aerobic
fitness and hence greater fat oxidation, may have been needed in order
to elicit significant changes in body composition in the INT group
compared to the CON group.

While caloric restriction has been reported to decrease lean mass
(Pritchard et al., 1997), resulting in a decline in RMR (Jakicic, 2002),
the addition of an exercise component to a diet intervention has been
shown to maintain (Tremblay et al., 1994) or attenuate this decline in
lean mass (Pritchard et al., 1997). This in turn can preserve RMR
(Treuth et al., 1996). The current study found that even though it
appeared that participants maintained their strict diet (as suggested by
similar kcal intake values recorded during weeks 1 and 12 and the need
to undertake regular weigh-ins at a weight loss agency), lean mass and
RMR were not significantly altered over the course of the intervention.
An explanation for the lack of significant increase in lean mass, and
consequently RMR in the INT group compared to the CON group, may have
been due to the mode of exercise undertaken in that walking is not
likely to induce significant increases in muscle mass. Lack of
significant change in fat-free mass in obese women following an 8-week
walking programme was also reported by King et al. (2001). Further, as
high-intensity exercise (85%-95% V[O.sub.2peak]) has been shown to
increase RMR, compared to lower intensity exercise (King et al., 2002;
Poehlman and Danforth, 1991), the use of higher intensity exercise
(>75% V[O.sub.2peak]) may have been needed in the current study in
order to elicit a significant increase in RMR in the INT group.

Exercise interventions in an overweight or obese population are
often associated with high attrition and poor adherence rates (Dishman,
2001; Jakicic and Gallaher, 2003), with a 53% attrition rate being
reported for an 8-week study where exercise was performed in a
laboratory by obese participants (King et al., 2001). This compares to a
35% attrition rate (30% for the CON group and 40% for the INT group) in
the current 12-week study, with adherence to exercise being 87.7% and
92.9% (NS) for the INT and the CON group, respectively. While these
adherence rates are comparable to those reported in a similar 12-week
exercise study by Murphy et al., (2002; 88.2 % and 91.3 for high and low
intensity exercise, respectively), the lower attrition rates may have
been due to the home-based nature of the intervention and /or the use of
split exercise sessions, which afforded participants flexibility in
performing their exercise. This greater freedom in performing exercise
is important, as lack of time has been reported to be the most common
reason given for discontinuing an exercise programme (Dishman, 2001).
Nonetheless, we acknowledge that exercise compliance (intensity,
frequency and duration) in a home-based programme is totally dependant
upon the accurate reporting of these details by the participant, with
this being a limitation to the current study.

Conclusion

This study was novel in that it assessed diet and exercise
(interval versus continuous aerobic exercise) in an obese population
using a home-based exercise protocol that required participants to
perform their exercise in two separate 15-min bouts. Results showed that
when compared to diet and continuous aerobic exercise, a combination of
diet and interval exercise resulted in significant improvement in VLDL-C
levels. Results also suggested that a home-based exercise programme that
allowed participants to split their exercise sessions over two bouts in
a day resulted in lower attrition rates than laboratory based
programmes. Future studies should include a control group, a larger
cohort, a longer intervention period, as well as assess the use of
higher intensity exercise during interval exercise.

Key points

* Twelve weeks of interval exercise and caloric restriction
resulted in significant improvement in very low density lipoprotein
cholesterol in an obese population, as compared to continuous aerobic
exercise and caloric restriction.

* Twelve weeks of either interval exercise or continuous exercise
resulted in similar improvements in aerobic fitness in an obese
population.

Acknowledgments

All financial costs of this project were covered by the School of
Sport Science, Exercise and Health at the University of Western
Australia. We would like to thank Dr Robert Vial for allowing us to
recruit our participants from his SureSlim agencies. We would also like
to acknowledge the assistance we received from Dr Andrew Maiorana (PhD:
Royal Perth Hospital) who monitored the 12-lead ECG tests.

Pritchard, J., Nowson, C. and Wark, J. (1997) A worksite program
for overweight middle-aged men achieves lesser weight loss with exercise
than with dietary change. Journal of the American Dietetic Association
97(1), 37-42.